4 The big difference between a maglev train and a conventional train is that maglev trains do not have an engine -- at least not the kind of engine used to pull typical train cars along steel tracks4. The engine for maglev trains is rather innoticeable. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track combines to propel the trains5.
5 The magnetized coil running along the track, called a guideway, repels the large magnets on the train's undercarriage, allowing the train to levitate between 1 to 10 cm above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push~ th train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetized coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust.
6 Maglev trains float on a cushion of air', eliminating friction. This lack of friction allows these trains to reach unprecedented ground transportation speeds of more than 500 kph, or twice as fast as the fastest conventional train. At 500 kph, you could travel from Paris to Rome in just over two hours.
词汇：
Levitate v. 悬浮 electrified v. 使带电
Levitation n. 悬浮 magnetize v. 使带磁
guideway n. 导向槽 line v.排列成行
propelb vt. 推进 underside n.下侧，下面
propulsion n. 推进 undercarriage n. 车盘
注释:
1. Maglev is short for magnetic levitation :maglev 是 magnetic levitation 的缩略词。
2. opposite poles attract and like poles repel each other: 异极相吸
